Day: December 22, 2009

This gun hunts only RFID tags.[mnt], who brought us laser gesture control, built this RFID Zapper but included so much more. Any good weapon has to sound mean, a feat he’s accomplished by incorporating an MP3 player into the rifle. The coil that zaps the RFID tag is powered by a photo-flash unit, but for visual feedback he’s got a second unit that flashes light to signal the demise of your German passport (see the video after the break).

It’s hard to believe we haven’t covered RFID Zappers yet. The concept came out of the Chaos Communication Congress a few years back. This method works by sending a very strong electromagnetic field through the RFID tag that causes it to burn out. There’s a wiki post on RFID Zappers but Firefox threw a certificate warning when we loaded it up; read at your own risk.

Subcycles is a sound controller application that [Christian] is using on the third multitouch display that he built. The screen is a sheet of acrylic in an aluminum frame. The image is rear projected onto an area covered with Digiline dispersion film. As with other projects that use the Community Core Vision package, a PS3 eye camera captures the touch information.

This build does a great job of including the audience in what the musician on stage is doing. [Chris] points out that the sight of artists staring at laptops on stage is becoming more and more common. The ‘Minority Report’-like interface that Subcycles uses makes not just for interesting music, but for an added visual reinforcement to the live part of the performance.

openSCAD uses a language somewhat reminiscent of C for creating models. A preview of the model is rendered alongside your code. Fully cross-platform, it runs on Linux, OS X, and Windows. Much like SketchUp, openSCAD can also extrude 2D outlines into models. This feature comes in very useful if one already has a set of technical drawings for a part. With no price tag, it’s pretty affordable during this costly season.

[j] sent in this nice writeup on how to revive a dead projector. he managed to pick one up for $20 that had a broken bulb. While the prices of bulbs have come down considerably, they can still be a couple hundred dollars. Being resourceful, he decide to just use a halogen bulb that he picked up at his local big box shop. In the photos, he’s using a 50w mr16 bulb. The results really aren’t too bad. Especially considering that his cost for the entire project is now roughly $25. He does, however suggest that a 100 watt bulb wouldn’t be a bad investment. His projector seems to need some cleaning and adjustment in the lenses as well, but for $25 it isn’t too shabby. We’ve had this submission for a bit, but it didn’t have any pictures of the projector actually working. During our conversation, we may have possibly suggested a picture we’d like to see. You can find it after the break.

The writeup and video embedded after the break do a great job of detailing the important differences between a stand-alone and a modular system. The good news is that the ATmega168 chips being used have a built-in interrupt based SPI protocol. Once wired correctly, a master control chip addresses each module separately, adding data to their buffer until a full frame has been transferred, then moves onto the next module.

Some of the caveats to this system such as digital transmission over long distances are discussed. We do wonder about power limitations if all LED’s in the marquee are illuminated at once. But that concern aside, if you’re thinking of playing around with an LED display don’t forget that there’s usually a huge price break for orders of 500 or 1000 LEDs!

The idea for the devices started off as a Christmas gift for his parents in-law. A boblight turns on when motion is detected. It then communicates (through radio) with the other boblights to turn them all on. If motion is not detected by any of the boblights for a length of time, they all turn off. Rather than having the user shut all of them off every morning, a light sensor is used to automate the task.

Each boblight is a common LED utility light combined with the board of an MS14A and added a 310MHz RF receiver. He even hacked the board by replacing the onboard PIC with a higher spec model. We think [Jonathan] did a great job at implementing an innovative concept.